Message: disassociated due to captive portal security failure

[agreen]

I had a device trying to connect to our guest SSID that had successfully connected before but wasn't able to connect to the internet until it "forgot" the SSID and then reconnected.  I looked in the logs and saw the 802.11 disassociation message was "disassociated due to captive portal security failure".  I haven't seen that one before, although looking through the logs shows several of these over the weekend on this network.  It sounds like it has to do with the splash page that we have setup on the guest SSID, but I  haven't been able to find a description of what that message means.  We haven't made any recent changes on the splash page.  Most new and returning devices can connect immediately, some returning devices have to forget the SSID and then connect again.  If anyone has any thoughts on this message and where I should look I would appreciate it.  
The AP showing the majority of those messages is an MR84 but I'm also seeing the message on an MR52 on the same network.  Both have up to date firmware. 

The spash page is set up as a simple acknowledgement of our network use agreement every 90 days.

Thanks.

[BlakeRichardson]

@agreen If you are only getting this with certain access points and not all of them I would open a support case. 

Have you been able to find any pattern on the affected device i.e. device type, OS, version issue on 2.4ghz and 5ghz etc. 

[yaoufi]

i There,

I have the exact same problem with my MR42.

Most users are able to connect but some of them started having this problem. Looking at the logs it says disassociated due to captive portal security failure.

Have you managed to solve this problem?

Regards

[agreen]

Still getting the issue here.  Seems to mostly be Apple devices.